prodigiouspython/Chapter_4/7_TLDR_about_Functions_arguments.ipynb

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   "source": [
    "# TLDR regarding function arguments 💡"
   ]
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   "source": [
    "Till now we have seen all the 4 types of arguments that we can use in functions."
   ]
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    "* Positional Arguments\n",
    "* Unnamed positional Arguments / VarArgs\n",
    "* Keyword-only Arguments \n",
    "* Keyword arguments / Varkwargs"
   ]
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   "source": [
    "Let's give it a shot with all the above arguments in a function 😎"
   ]
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    "The complete syntax of a function eliding varargs and keyword arguments defined in [PEP-570](https://www.python.org/dev/peps/pep-0570/) would be as:\n",
    "\n",
    "```Python\n",
    "def name(positional_only_parameters, /, positional_or_keyword_parameters, *, keyword_only_parameters):\n",
    "```"
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    "`Example:`"
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   "source": [
    "Let's build a complete function with all the types of arguments 😎."
   ]
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    "def function(positional_only, /, position=\"🐍\", *varargs, keyword_only, **keyword):\n",
    "    print(f\"{positional_only=}\")\n",
    "    print(f\"{position=}\")\n",
    "    print(f\"{varargs=}\")\n",
    "    print(f\"{keyword_only=}\")\n",
    "    print(f\"{keyword=}\")\n",
    "\n",
    "    # datatype of varargs and keyword.\n",
    "    print(f\"The datatype of varargs is {type(varargs)}\")\n",
    "    print(f\"The datatype of keyword is {type(keyword)}\")"
   ]
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   "source": [
    "Let's call our beautiful function ♥️"
   ]
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    "function(\n",
    "    \"Python\",\n",
    "    \"♥️\",\n",
    "    \"Python\",\n",
    "    \"is\",\n",
    "    \"Cool\",\n",
    "    keyword_only=\"😋\",\n",
    "    key1=\"value1\",\n",
    "    key2=\"value2\",\n",
    ")"
   ]
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   "source": [
    "The above calling of function can also be written as:"
   ]
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    "function(\n",
    "    \"Python\",\n",
    "    \"♥️\",\n",
    "    *[\"Python\", \"is\", \"Cool\"],\n",
    "    keyword_only=\"😋\",\n",
    "    **{\"key1\": \"value1\", \"key2\": \"value2\"},\n",
    ")  # Unpacking."
   ]
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   "source": [
    "Let's make `position` be it's default value."
   ]
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    "function(\n",
    "    \"Python\",\n",
    "    *[\"Python\", \"is\", \"Cool\"],\n",
    "    keyword_only=\"😋\",\n",
    "    **{\"key1\": \"value1\", \"key2\": \"value2\"},\n",
    ")"
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   "source": [
    "Ouch, we see that `position` has taken the `Python` as it's value which we intended to be one of the value of our `varargs`. The solution for this is to pass our `*[\"Python\", \"is\", \"Cool\"]` as keyword argument like `varargs=[\"Python\", \"is\", \"Cool\"]`. **NOTE** that there won't be unpacking symbol `*` here."
   ]
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    "function(\n",
    "    \"Python\",\n",
    "    varargs=[\"Python\", \"is\", \"Cool\"],\n",
    "    keyword_only=\"😋\",\n",
    "    **{\"key1\": \"value1\", \"key2\": \"value2\"},\n",
    ")"
   ]
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   "source": [
    "We can even notice that in the above example, we have passed `varargs=[\"Python\", \"is\", \"Cool\"]`, but in the output the datatype of varargs is printed as tuple. Not just in above example, in all the above examples, we can see that `varargs` is `tuple` and `keyword` is `dictionary`."
   ]
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   "metadata": {},
   "source": [
    "💡 Unnamed Positional arguments datatype is always tuple and keyword argument datatype is always dictionary ."
   ]
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